Installation switching devices of this generic type are, for example, circuit breakers, residual current devices, motor protective switches, and main line circuit breakers. Within an insulating material housing, they have a switching apparatus, by means of which the current path which runs between an input terminal and an output terminal in the interior of the installation switching device can be interrupted or switched off, and can be switched on again.
The switching apparatus in the interior of the insulating material housing can in this case be switched on and off by an operator from the outside by means of a switching handle, which can be pivoted or rotated at least between a switched-on position and a switched-off position. The side of the installation switching device on which the switching handle is accessible for operation is referred to in the following text as the front face. The switching handle interacts in a suitable manner, which is known in principle, with the switching apparatus which is accommodated in the interior of the insulating material housing, such that the current path is switched on when the switching handle is in the switched-on position, and is switched off when the switching handle is in the switched-off position.
An installation switching device which switches one and only one current path between an input terminal and an output terminal is referred to as a single-pole installation switching device. If a plurality of current paths between a plurality of input terminals and a plurality of output terminals can be switched within one insulating material housing, then this is referred to as a multipole installation switching device. For example, three individual current paths, which each run between three input terminals and three output terminals, could be switched on or off at the same time by operation of a single switching handle in a three-pole installation switching device. A three-pole or multipole installation switching device can also be produced by arranging a plurality of single-pole devices in a row with their broad faces adjacent to one another, in which case the switching handles of the individual single-pole devices would need to be connected in a suitable manner, which is known in principle, in order to allow all the poles to be switched jointly.
It is often desirable to adopt suitable measures to ensure that the installation switching device may be operated only by authorized personnel. For this purpose, the switching handle is lead-sealed in one switch position, for example in the switched-on position, and the lead-seal may be released only by personnel authorized to do so, as a result of which manual disconnection can be carried out only by an operator who is authorized to do so. In precisely the same way, it would, of course, also be possible to use a lead-seal to ensure that only a person who is authorized to do so can switch the device on by hand.
A known technical apparatus for lead-sealing of the switching handle comprises the fitting of a front-face cover to the switching handle, with this cover being lead-sealed by means of a lead-sealed lock, for example, or a lead-sealing wire. However, the additional cover part required for this purpose could also be dispensed with, for cost reasons.
Other known technical apparatuses dispense with an additional cover part and, instead of this, provide a slide which is mounted in the switching handle, can be pulled out of the switching handle and overhangs the switching handle in the pulled-out state, with the part which overhangs said switching handle engaging in a holding groove which is located on the front face surface and corresponds with the switching handle in the lead-sealed position, where it can be lead-sealed in the pulled-out state. One example of an apparatus such as this is disclosed in DE 10 2006 058987, using the example of a lead-sealable rotary handle.
For example, in the case of installation switching devices having switching handles which can be moved linearly or can be tilted, it is known for two thin holes to be provided on the front face, which are separated transversely with respect to the movement direction of the switching handle and through which a lead-sealing wire can be passed, in such a way that the switching handle can be prevented from pivoting, by means of the lead-sealing wire or a lead-sealed lock. The housing of the installation switching device in this case assumed to be a standard housing, with there being no significant difference in the external contour between a lead-sealable embodiment and a normal embodiment. The holes on the front face may therefore only be made thin since, otherwise, it would be necessary to form a thicker bead in order to accommodate thick holes. Lead-sealing by means of a lead-sealed lock is therefore not possible, since the hasp of a lead-sealed lock is considerably thicker than a normal lead-sealing wire.